Facile Regeneration Strategy for Facet-Controlled Nanocatalysts via the Dissolution–Reprecipitation Process Promoted by an Organic Modifier

Highly active facet-controlled nanocatalysts deteriorate readily via surface-atom migration during their use. This study develops a method for regenerating a degraded facet-controlled nanoparticle catalyst by reorientation of surface crystalline structure via the dissolution–reprecipitation process using an organic modifier. The supercritical hydrothermal treatment with the carboxylic acid modifier changes the CeO2 nanoparticles morphology to cubic-like over time to expose the (100) facet. This morphological transformation dynamics suggests that the modifier not only stabilizes the (100) facet but also accelerates the dissolution–reprecipitation process, promoting facet modification and catalyst regeneration. The facet-controlled nanocatalyst regeneration is verified experimentally by the recovery of oxygen storage capacity in the CeO2 nanoparticle, which is an indicator of the catalytic activity.